Fat body expressed yolk protein genes in Hyphantria cunea are related to the YP4 follicular epithelium yolk protein subunit gene of pyralid moths

Abstract

cDNA clones for two of the yolk proteins, YP1 and YP2, produced by the fat body of the moth, Hyphantria cunea, were sequenced and found to be homologous to the follicular epithelium yolk proteins of pyralid moths. Both cDNA clones coded for polypeptides of 290 residues and the deduced amino acid sequence identity between YP1 and YP2 was very high (79.0%). Analysis of the secondary structure of the predicted polypeptides suggests that YP1 and YP2 do not form heteromeric proteins because of differences in secondary structure due to the lack of alpha helices in YP1. Northern blot analysis showed that the transcripts for YP1 (1.2 kb) and YP2 (1.1 kb) were present primarily in the female fat body with only trace levels detectable in the ovary of the adult female. In a developmental study, the YP1 and YP2 transcripts were first detectable in 10-day-old pupae and increased into the adult stage. These results suggest that the YP1 and YP2 genes in H. cunea have been recruited to replace the vitellogenin gene as the primary source of yolk proteins. During this process they have acquired a modified pattern of expression that is different from homologous genes reported in pyralid moths. The assessment of the evolution of proteinaceous yolk in these moths should serve as an excellent model for the evolution of gene recruitment.

Characterization and functional analysis of hsp21.8b: An orthologous small heat shock protein gene in Tribolium castaneum

“…In addition, the fat body stored a great amount of lipid not only provides energy for growth, but is essential for reproduction (Arrese & Soulages, ). And the yolk‐proteins which provide nutrients for the developing embryos are expressed in the ovarian follicle cells and fat body of adult females in insects (Cheon et al., ; Pines, Lubzens, Harry, & Applebaum, ). Thus, knocking down Tchsp21.8b finally caused a low oviposition and egg hatching rate (Figure ).…”

Immune activation of apolipophorin-III and its distribution in hemocyte from Hyphantria cunea

“…4). Usually, yolk protein-1 transcript was not detectable during larval and early pupal stages, but first detectable in 10-day-old pupae of H. cunea (Cheon et al, 2003). The injection of purified yolk protein-1 into larvae did not induce the two major antimicrobial peptides, suggesting that the insect could specifically use apoLp-III to activate immune reaction.…”

“…4). Control proteins such as yolk protein-1 (Cheon et al, 2003) and storage protein-1 (Seo et al, 1998) with the same amount of proteins as in the apoLp-III solution were injected into larvae to compare the effect by the injection of its own protein (Fig. 4).…”

Comparative and functional genomics of lipases in holometabolous insects

“…Among the Lepidoptera it is clear that some species like the fall webworm Hyphantria cunea (a noctuid) have replaced vitellogenins with acid lipase-like proteins as their major yolk proteins (Cheon et al, 2003). On the other hand bombycid and pyralid moths retain functional vitellogenin, albeit oogensis and embryogenesis can proceed in its absence (Yamashita and Irie, 1980).…”